Pump diaphragm in Holley 1bbl carb kit is wrong, Where do I get one?

[WH23G3G]

I'm rebuilding the 1bbl Holley 1920 from my 1965 225 Slant Six that I've got in a Plymouth. I bought the only kit available from the parts stores for it. It was a GP Sorensen kit number 96-191B. There are two pump diaphragms in the kit and neither are close to the one that came out. The two in the kit has a flat stem and my original has a cylindrical stem with a spring and a check ball holding it in place. The only other things included in the kit are the base gasket, base space, needle & seat, new economizer diaphragm and gasket, push rod ball, fuel bowl gasket. There's not a whole lot to this carb. But do I need to find another kit with the correct pump diaphragm or can I reuse this one? I don't know where to find a new one at. All the parts stores here have the same kit. Is it safe to reuse the old one? I don't know how to tell if it was any good. Here is my original one at the left and the two ones included in the kit.